There is nothing magic about a cassette, nothing bewitching about an object that can be taken apart and reassembled or fixed with a pencil. A small rectangular box of plastic in which magnetized tape moves back and forth between miniature spools, it is, from today’s vantage, a hopelessly antiquated format. At a time when most of us listen to music that exists only as data, on soundless players that cannot be pried open, the cassette displays its modest mechanics all too transparently. Peer inside the deck as you slide in a tape in, and you see a tiny, busy factory world of belts, wires, and interlocking gears. Press play, and even before the first track begins, you hear a series of hisses and squeals and the faint whir of the motor. When the side ends: a harsh click. Even in the 1980s, when the cassette tape represented the apex of consumer technology, its advances—the workmanlike auto-reverse button; various gradations of Dolby; “IEC Type II High (CrO₂) Position,” whatever that means—seemed puny, stopgaps to tide us over until we could engineer more elegant solutions.

Given that the cassette is widely regarded as a nostalgic curio today, few people were surprised when Sony discontinued production of the Walkman, their once-iconic portable cassette player, last April. The greater shock, for many, was the realization that Sony was still manufacturing Walkmen at all. While we mourn the player’s death and await the iPhone 5, it would be a mistake to dismiss the cassette as merely a transitional technology. Rather, it offered its user a previously unimaginable degree of autonomy, a freedom that is today familiar to us, and was the first music format to raise thorny questions about the concept of fair use and about what it means to own a piece of music.